Question

Harrison has two $1 bills, eight $5 bills, six $10 bills and four $20 bills. He randomly chooses a bill, replaces it, then chooses another. What is the probability that he chose a $5 bill then a $10 bill?

Answer 1

The probability that Harrison chooses a $5 bill then a $10 bill is 3/25

Explanation:

Harrison has a total of 20 bills. When he chooses a bill and replaces it, there is still the same number of bills left, so each choice is independent of the other.

To calculate the probability that Harrison chooses a $5 bill then a $10 bill, we need to find the probability of each individual event and multiply them together.

The probability of choosing a $5 bill on the first draw is 8/20, or 2/5, since there are 8 $5 bills out of 20 total bills. After replacing the bill, there are still 8 $5 bills out of 20 total bills.

The probability of choosing a $10 bill on the second draw is 6/20, or 3/10, since there are 6 $10 bills out of 20 total bills.

To get the probability of both events happening, we multiply the two probabilities:

(2/5) x (3/10) = 6/50 = 3/25

Therefore, the probability that Harrison chooses a $5 bill then a $10 bill is 3/25.